[tex-live] installer and no wgetrc

[Karl Berry]

I've removed the TeX Live wgetrc file from the installer, so that users'
wgetrc's (specifying proxy information, etc.) should now have their
normal effect.

The changes will be in tonight's update of install-tl.  No one but me
has tested it, so please try it if you like.  It shouldn't have any
particularly visible changes in behavior.  (I just moved our custom
settings from wgetrc to the command line, basically.)

Thanks,
karl